Fluid seal



April 19, 1949.

voYTEcH FLUID SEAL Filed Sept. 20, 19415v Patented Apr. 419, 1949 FLUIDSEAL Charles F. Voytech, Chicago, Ill., assignor to Crane -PackingCompany, Chicago, Ill., a corporation of Illinois Application September20, 1945, Serial No. 617,467

This invention relates' to mechanical seals for effecting a fiuid-tightseal between relatively rotatable or movable parts and particularly tothat type of Seal which employs radially disposed' surfaces foreffecting the seal.

Mechanical seals in wide use at the present time are comprised of anaxially fixed surface on one of two relatively rotatable elements to besealed. a rubbing sealing surface on a sealing washer cooperating withthe first surface, a flexible compressible sealing element connectingthe washer to the other of the rotatable elements and a spring forexerting a pressure upon the washer in the direction'of thefirst-mentioned sealing surface to maintain the sealing surfaces incontact with one another. The fiexible compressible sealing element isgenerally made of rubber and is molded to the exact size and shaperequired. Since the machinery in which the seals are to be used variesgreatly as to the size of the opening to be sealed and the nature andpressure of the fluid to be retained by the sea] in the machinery it isnecessary for the manufacturer to invest large sums of money in moldsand dies for the various sizes and types of seals which he proposed tomarket in order to cover the entire field.

The general object of this invention is to provide a seal which issufiiciently compact and inexpensive to render it salable as an ordinarylow pressure closure for bearings and the like and yet which issufliciently rugged to be used as a shaft Seal for pumps and otherhydraulic machinery in which relatively high pressures on the order ofseveral hundred pounds per square inch may be encountered.

A specific object of this invention is to design' a mechanical sealwhich seals upon a radial surface, the design being such that theflexible member of the seal telescopes tightly into the sealing washerof the seal and is adapted to be preloaded upon a cylindrical surface.

Another specific object of this invention is to provide a seal which isself-contained such that the sealing washer, the sealing element and thespring may be handled as a unit.

These and other objects -and featuresof this invention will becomeapparent from the following description when taken together with theaccompanying drawings, in which Fig. 1 is a section through a sealembodying the features of this invention shown applied to a Pump;

Fig. 2 is a development of a fragment of the 'spring and the ferrule towhich it isapplied;

7 Claims. (Cl. 286-11) lines 3`-3 showing the means for driving thewasher of Fig. 1;

Fig. 4 is an elevation of a seal ernbodying the features of thisinvention shown applied to a high-pressure hydraulic appara-tus;

Fig. 5 is a section through the seal of this invention showing the sealused as a closure for either low or high-pressure applications; and

Fig. 6 is a section through a modification of the seal of F'ig. 1wherein the spring is mounted internaliy of the seal.

Referring now to Fig. 1 for a detailed description of the invention,there is shown a pump housing lu formed with a cavity ll therein andWith an opening |2 through which passes a shaft |3. Said shaft 13 isthreaded at 14 to receive a pump impeller |5 (shown fragmentally), saidpump impeller |5 having a substantially radially disposed wall |6 whichforms one wall of ,the cavity II. Pump housing IO is also formed with anannular axially extending projection Il on which is formed a sealingsurface |8. Said surface I 8 is substantially radially disposed withreference to shaft |3 and is suitably machined by grinding or the liketo provide a smooth sealing surface.

Cooperating with sealing surface [8 is a washerJ |9 having an annularnose portion 20 provided' with a radial surface 2| which is in slidingcontact with surface |8 and constitutes the means by which a seal iseffected between the relatively stationary housing and the rotatableshaft |3. On the back face of washer |9 is formed a recess, the recessbeing defined by a radial wall 22 and a cylindrical wall 23. The purposeof the recess will be described hereinafter. One. or more notches 24(Fig. 3) is formed on the interior ol' washer |9, said notchescooperating with curved lugs 25 which extend outwardly from the other-.Wise cylindrical surface of a clamping band 26. The lug and notchconnection between band 26 and washer |9 constrains the washer to rotatewith band 26 but permits said washer |9 to move axially with respect tosaid band 26.

The sealing element which effects the seal between washer |9 and shaft13 is shown generally at 21 and is comprised of a relatively thicklcylindrical sleeve 28 having an internal diameter which is slightlysmaller than the external diameter of shaft |3 such that a snug fit willbe effected therebetween. Said sealing element 21 is also provided atits outer periphery with a ring 29 which fits snugly into the recessformed by radia] wall 22 and cylindrical wall 23 of washer 19.Connecting ring 29 and cylindrical portion 33 of the flexible element isa diaphragin 33 which is preferably made slightly thinner than eitherthe ring 23 or the cylindrical section 23 so as to rupture any pressureswhich might be encoun- V tered in the installation shown.

The cylindrical section 23 of the sealing element 21 is pressed tightlyupon shaft |3 'by band 26, the extemal diameter of the sleeve portionbeing slightly greater than the internal diameter of band 26 so that apreloading effect is secured when band 26 and sealing element 21 areassembled upon shaft |3. A ferrule 3| flts over the ring 23 on flexibleelement 21 and compresses said ring radially inwardly upon thecylindrical wall 23 of washer |3 so that said washer I! is in effectclamped to the ilexible element 21 by ferrule 3|. Said ferrule 3| has aradially inwardly extending iiange 32 to which may be secured two ormore double cantilever type Springs 33 (Fig. 2), the strength of whichis selected to provide sufficient force to maintain washer |3 and itssurface 2| in sealing engagement with surface |3 at all times and underthe predetermined conditions of wear. The individual cantilever sprlngs33 may be secured to ilange 32 by means of rivets 33 or by any othersuitable means such as soldering, or the like. The contour of spring 33is preferably such that the means for securing the springs to the fiangewill not be stressed as the springs are deflected.

The seal just described may 'be assembled at the factory by firstassembling washer |9 upon a driving band 26 with the notches 23 properlyindexed relative to the lug 23 and the sealing element 21 may then beslipped into band 26 and into the recessformed'by walls 22 and 23 to theposition shown, and finally. ferrule 3| is pressed over the ring 23thereby eifectively compressing ring 23 into the recess by the ferrule.There is now assembled a unit which includes all of the necessaryelements of a seal and which is ready for installation merely bypress'ing the entire unit over a suitable shaft such as shaft |3 andpushing the unit back until sealing element 2'l strikes an abutment suchas wall |6 on pump impeller |3. Alternatively, if the shaft |3 isaxially fixed, the assembled sealing unit may be pressed into place fromthe right as viewed in Fig. '1 'by removing impeller |3 and thenpressing the unit upon the shaft to approximately the position shown,after which the impeller is screwed back in place.

Referring now to Fig.. 4 for a description of a modification of the sealof this invention as adapted .to high-pressure installations, there isshown al shaft 33 passing through a closure plate 36 which in tum issecured by means (not shown) to a housing 31. In the space defined 'byhousing 31 and shaft 33 arel located the sealing element 21, the ferrule3|, the springs 33 and the clamping band 26, all of said elements beingidentical with those bearing similar reference characters in Fig. 1. Itwill be noted that flange 36 and the cylindrical sleeve 23 of thesealing element 21 form in effect either a collar compressed upon theshaft or a stepped region on the shaft. To

shoulder or collar on the shaft. Thus the present seal is well suitedfor operation with a sealing washer which is designed to operate in arecessed portion of a shaft.

Thus in the Fig. 3 modiflcation there is shown a washer 33 which isprovided with the radially disposed wall 22 and cylindrical wall 23shown in Fig. 1 to receive the ring portion 23 of the sealing element21. but is also provided with an extension 33, the internal diameter ofwhich ia smaller than the external diameter of clamping band 23 butwhich is slightly larger than the diameter of shaft 33 so as to providea certain amount of clearance therebetween. The outer radial surface 33is suitably ilnished and constitutes one of the sealing surfaces of theseal. Said sealing surface 33 cooperates with a ground and lappedsealing surface 3| formed in a seat 32 which is supported by means of aresilient compressi'ble ring 33 pressed into a recess 33 in closureplate 36. An abutment is provided for the spring 33, the abutmentcomprising a washer 33 which is held against axial movement to the rightas seen in Fig. 4 by means of a snap ring 36.

The unit shown in Fig. 4 is assembled in exactly the same manner as theone shown in Fig. 1. The difference in the shape of the washer 33 doesnot require any different technique for assembling it relative to thesealing element 21 and the driving band 26. Obviously since the outsidediameter of sealing surface 33 on washer 33 is only slightly larger thanthe outside diameter of driving band 26, the fluid pressure acting onthe left-hand side (Fig. 4) of washer 33 will be substantially balancedby the fluid pressure acting upon the sealing element 21 and so much ofit as is effective to transmit the pressure to the washer itself. Thedegree of balance may of course be varied by varying the outsidediameter of sealing surface 33 relative to the outside diameter ofdriving band 26.

Referring now to Fig. 5 for a description of the way in which thesealing unit of this invention may 'be used as a closure either for ashaft or for some other rotatable machine element such as a bearing,there is shown a housing 31 to which is secured a closure plate 33having an opening 33 therein through which a shaft 30 passes. In thereduce the fiuid pressure upon the sealing sur- ;which is mounted on adriving band 23 which.l

in turn, is pressed upon cylindrical portion 23 of sealing element 21.Said cylindrical portion 23 however instead of being compressed upon ashaft is pressed upon a tube 33 which may have a fluidtight press-flt inopening 33 in closure 33. The ring portion 23 of sealing element 21 iscompressed or preloaded into the recess formed by walls 22 and 23 inwasher |3 by the ferrules 3| as previously described with reference toFig. 1.

The spring 33 bears directlyl upon a'radially disposed wall 33 onclosureplate 33.

To assemble the' seal of Fig. 5 closure plate 33 is placed ilat upon aplate or bench with wall 36 facing upward and then tube 33 is pressedinto opening 33 until it strikes the plate or bench. Next the seal unitincluding the washer and sealing element 21 is slid over the tube 33until the sealing element 21 abuts wall 33. The closure plate 48 maythen be secured to housing 41 in any suitable manner (not shown) Themodification shown in Fig. 6 diifers from those previously described inthat the spring is retained between the washer and the sealing elementso that no external abutment for the spring is necessary. The washer |9may be identical to those disclosed in Figs. 1 and 5 and hence isprovided with a recess formed by a substantially radial wall 22 and acylindrical wall 23. The sealing element for washer 9 is shown at 51 andis comprised of a substantially cylindrical portion 58 similar in size,shape and function to cylindrical portion 28 of sealing element 21 inFigs. 1 and 5; a relatively thick ring 59 which fits into the recessformed by surfaces 22 and 23 and a relatively thinner diaphragm portionconnecting the cylindrical portion 58 and the ring 58. Intermediatewasher |9 and cylindrical portion 58 is a clamping band 6| having asubstantially cylindrical portion 52 contacting the outer surface ofcylindrical portion 58 of sealing element 51 and a radially disposedfiange 63. As in the previously described forms, washer |9 is providedwith notches 24 into which are fltted driving lugs 25 formed in drivingband 6|. A ferrule is placed against ring 59 and extends radiallyinwardly in the vicinity of driving band 5|. Suitable notches 51 may beformed in ferrule 56 to enable the ferrule to pass over the driving lugs25. The Springs 33 are secured to ferrule 66 in such a manner that thenotches 25 are located between the ends of the Springs and hence theSprings do not interfere with the movement of the ferrule past the lug25. The free ends of the spring 33 abut radially disposed flange 53 ondriving band V5| and tend to separate ferrule 66 and fiange 53. Thisresults in an axial force on washer |9 since cylindrical section 58 ofthe sealing element 5'| is-clamped to a shaft or the like and will causewasher |9 to be urged against the corresponding sealing element on thehousing or the closure plate for the housing to which the element may besecured. Alternativeiy, the springs 33 may be secured to the flange 53and bear against ferrule 56. It will .be observed that diaphragm isbowed so that relative movement between the portion of the diaphragm 60in contact with flange 53 and ring 59 is readily possible.

The form shown in Fig. 6 may be used in the same installations as theforms shown in Figs. 1 and 5. Obviously a washer such as washer 33 ofFig. 'i may be used in place of washer |9 in the Fig. 6 construction tosecure a balanced seal. Because of the presence of fiange 63, however,it is also possible to use the seal of Fis. 6 in an installation wheretwo substantially parallel relatively rotatable radial walls areavailable for sealing rather than a cylindrical surface and a. radialsurface as in Figs. 1, 4 and 5. Thus the'sealing unit of Fig. 6 may bedropped as a whole into a recess in the same manner as water pump sealsfor automobile engines are at present installed.

When relatively high internal pressure or considerable swelling of thesealing element 51 are encountered, an additional rigid band lsuch as 58may be used. This band is preferably such as to exert a radially inwardcompressive force upon ring 59 of the fiexible sealing element V5'l andmay have an inturned edge 89 to assist in locating the band relative tothe ring 59 and also to hold washer |9 in place.

Thus the sealing devices herein described comprise complete units whichmay be adapted for use either as shaft seals or as closures and with theuse of interchangeable washers can be balanced hydraulically to anydesired extent to relieve the fluid pressure on the sealing surfaces.The various parts of the sealing device can be assembled readily, andwhen assembled, can be handled together with the spring as a singleunit. In one modification an external abutment is required for thespring and in another modification the spring and abutment areself-'contained and require no additional element for the operation ofthe seal. The iiexible compressible sealing element used in allmodiflcations is relatively simple to mold, particularly the onedisclosed in Figs. 1, 4 and 5.

It is understood that in addition to the modiflcations disclosed, othermodifications might suggest themselves to those skilled in the art andthe scope of this invention .therefore is not to be limited to themodifications used herein for illustrative purposes but is to bedetermlned by the appended claims.

What is claimed is:

1. A device for eflecting a seal between relatively movable elements.said device comprising a sealing washer, a ilexible compressible sealingmember having a substantially cylindrical portion for engagement withone of the elements and a diaphragm extending from the cylindricalportion into engagement with the washer, a band supported solely by thecylindrical portion andv adapted to compress the cylindrical portionupon the element engaged thereby, said band telescopi ing within thewasher and having an axially slidable driving connection with the washersuch that relative rotation between the washer and band 'is preventedbut relative axial movement between the washer and band is possible, andmeans for clamping the outer end of the diaphragm to the washer toeffect a fluid-tight seal therebetween.

2. A device for eifectlng a seal between relatively movable elements,said device comprising a sealing washer, a flexible compressible sealingmember having a substantially cylindrical portion for engagement withone of the elements, a diaphragm extending from the cylindrical portionand a relatively thick ring, said washer having a recess' to receivesaid ring, a band supported solely by the cylindrical portion andadapted to compress the cylindrical portion upon the element engagedthereby, said band telescoping within the washer and having an axiallyslidable driving connection with the washer such that relative rotationbetween the washer and band is prevented while relative axial movementbetween the washer and band is possible, and means for clamping the ringof the flexlble compressible sealing member to the washer to effect afluidtight seal therebetween.

3. A device fo'r eifecting a seal between relatively movable elements asdescribed in claim 2. said means for clamping the outer end of thediaphragm to the washer comprising a ferrule having a cylindrical'region adapted to encircle the ring and having also` a substantiallyradially disposed fiange, spring means secured to said flange so as tobe movable therewith, and an abutment for said spring means whereby saidspring will exert an axial force upon `the washer.

4. A device for eifecting a seal between a pair of relatively rotatableelements, one of which has an opening through which the other passes.said device comprising a sealing washer, a fiexible 'compressiblesealing member having a substantially cylindrical portion and adiaphragm extending from the cylindrical portion into engagement withthe washer, a. tube held by the relatively rotatable element having theopening and being in sealing engagement therewith, a band supportedsolely by the cylindrical portion and adapted to compress thecylindrical portion upon the tube, said band telescoping within thewasher and having an axially slidable driving connection with the washersuch that reiative rotation between the washer and band is preventedwhile relative axial movement between the washer and band is possible,means for clamping the outer end of the diaphragm to the washer toefl'ect a fluid-tight seal therebetween, and spring means secured to theclamping means and reacting against the said one of the relativelyrotatable elements to urge the washer axially into sealing engagementwith the other of the said relatively rotatable elements.

5. A device for eflecting a seal between relatively rotatable elementsas described in claim 4, said band compressing a portion of thediaphragm against the relatively rotatable element having the opening soas to efiec't a seal between the sealing. member and relativelyrotatable element directly.

6. A device for efiecting a seal between relatively movable elements.said device comprising a sealing washer, a flexible compressible sealingmember having a substantially cylindrical portion for engagement withone of the elements Vto be sealed and a dia-phr'agm extending outwardlyand bent back 'upon .the cylindrical portion into engagement with thewasher, a band adapted to compress' the cylindrical 'portion upon theelement engaged thereby, said band supported solely by the cylindricalportion and telescoping within 'the washer and having an axiallyslidable driving connection with lthe washer such that relativerot-ation between the washer 'and band is prevented but relative axialmovement between the washer and band is possible, 'and spring meanswithin |the confines of the diaphragm and 8 reacting at one end againstthe band and at the other end against the washer.

'1. A device for ei'tecting a seal between relatively movable elements,said device comprisinz a seaiing washer, a fiexlble compressible sealingmember having a. substantially cylindrical portion tor engagement withone o! the elements to .'be sealed and a diaphragm extending outwardlyand bent back so as to surround the washer, a 4

band supported solehr by the cylindrical portion and adapted to compressthe cylindrical portion upon the element engaged thereby, said bandtelescoping within the washer and having an axially slidable drivingconnection with the washer such that relative rotation between thewasher and band is -prevented but relative axial movement between ;thewasher and band is possible, a second band compressing the portionof'the ilexible element surrounding the washer against the washer, afiange extending radially outwardly from the first-mentioned band, andspring means acting in compression between the washer and flange andlocated within the sealing element.

CHARLES F. VOYTECH.

REFERENCES CITED The following references are of record in the nie ofthis patent:

